Oil burner



W. 8. GRANT April 14, 1931.

OIL BURNER Original Filed Dec. 5, 1927 2 Sheets-Sheet 1 P 1931-. w. 5. GRANT 1,800,726

OIL BURNER Original Filed Dec. 5, 1927 2 Sheets-Sheet 2 gwuentoz of a new and novel oil burner an Patented Apr. 14, 1931 UNITED STATES PATENT OFFICE mm 8. GRANT, 015 DETROIT, MICHIGAN, ASSIGNOR TO HENRY D. MACKAYE, F

' DETROIT, MICHIGAN on. steam Original application filed December 5, 1927, Serial No. 237,947. Divided and this application filed August 20, 1928. Serial No. 300,771.

This-invention relates to oil burners for various types of furnaces or heating apparatus, the principal object being the rov1s1on various parts used inconnection therewith and is a division of my application for Letters Pat-- ent oi -the United States for improvements in oil burners filed December 5, 1927, and

Y Serially Numbered 237,947.

Another object is the provision of an oil burner in which a constant heating fire is maintained, such fire being capable of. being regulated to a plurality of intensities for the purpose of maintaining a room or the like at a substantially constant temperature.

Another object is the provision of an oil burner in which the conventional pilot light with all of its attending dangers is eliminated, and a constant burning of the oil is maintained.

Another object is to provide an oil burner in which the flame is maintained in either high or low positions, such low positions'being such as to maintain a flame of such proportions as to impart a substantial heating -eflect to the furnace or heating apparatus in connection with which it is used. Another object is to provide an oil burner in which the heating flame is never extinguished, thereby maintaining the associated heating apparatus at a temperature between relatively narrow limits, eliminating the lag in bringing the apparatus to the predetermined high temperature limit so common in the conventional types of oil burners now on the market, and eliminating the use of the conventional pilot light with its attendant dangers.

Another object is the provision ofa device located within the burner mechanism of an oil burnin apparatus and consisting of a ll or sump containing a composition for the retention of combustible fluids which are ignitable for constant burning therefrom, and so constructed as to allow for a metered quantity of air for mixture with the burning gases for a given period of time exclusive of the delivery of oil 'to the burner combustion receptacle but located integral therewith and in no way dependent upon or for its action or source of supply from the main combustion receptacle.-

' Another object is the provision of a device located within the burner mechanism of an oil burning apparatus serving as a separate unit for supplying ametered combustion for the purpose of a primary constant fixed low fire, the ignition of which continues even after the main source of oil has for any one of many reasons become exhausted, and so designed and constructed as not to be atfectedby the air from the blower fan in the event that the fire in the main combustion receptacle shall become extinguished.

Another object is the provision of a design for oil burning mechanism which positively precludes any possibility of a premature explosion of gases in the combustion chamber of the boiler or other heat transmitting apparatus through delayed ignition when the .w1th reference to the accompanying drawlngs, and then claimed, having the above and other objects in View.

Inthe accompanying drawings which illustrate a suitable embodiment of the present invention and in which like numerals refer to like parts throughout the several different views,

Fig. 1 is a plan View of the oil burning apparatus the furnace being shown in hori zontal section.

Fig. 2 is a side elevation of Fig. 1' partially in section, the-muffler being removed to better illustrate the construction of the same.

air supplied to the.

Fig. 3-is an enlarged vertical sectional view taken on line 3-3 of'Fig. 1', longitudinally through the oil burner nozzle and centrally through the-fire pot.

Fig. 4 is an enlarged sectional view taken on line 4-4 of Fig. 3;

, an oil burnlng furnace is a fire pot designated generally in thereof. Supported Figs. 1 and 2 as 17, which is supported from the floor of the ash pit bythe standard 18 which adjustably engages the apertured boss 19 formed on the outer surface of" the fire pot 17, the fire pot 17 being locked in vertical adjusted position by. means of the set screw 20. Integral with the fire pot 17 is the nozzle or venturi 21 which enters the to the interior surface exteriorly of the furnace 6n the legs 22 is the stand 23 which supports the electric motor 24. On one end of the motor 24 is secured a fan or blower 25 which may be of any conventional type, but for the purpose of illustration is shown as a centrifugal type of blower, it being provided with a discharge passage 26 which. extends through the door 27 of the ash pit 16 and is socketed in the outer end of the venturi 21. The air intake for the fan 25 extends axially from the fan casing on the side thereof opposite the motor 24 and receives at its free end a muffler or silencer 29. This serves to muflle the sound of the air rushing thr'oughthe fanand its passages and also serves to mufile the noise of combustion of the gases in the fire pot '17 which tends to travel back through the passage 26 and out through the fan 25. I y

The oil is conducted through the pipe 42 to a valve mechanism having a casing 43 fire pot at a tangent and then through the pipe [44 to another ing in the nozzle end 49 which is provided.

valve mechanism having a casing 45. From the casing 45 the oil is conducted throu h the pipe 46 to a third valve mechanism, t e casing of which is indicated as 47, and thence through the pipe 48 into the interior of the fan passage 26, the pipe 48 terminatwith a plurality of radial openings 50 for the escape of the oil. The purpose of. the fore oing valves which-are inserted in the oil line will be described later.

As set forth in the objects of the present invention, the construction herein disclosed employs no pilot light, the fire never being extinguished, but instead, being merely checked when the room or other space being heated has reached a desired maximum temperature, the mechanismbeing constructed to'providea high and low the. It is obvito be fed to themechanism than for high fire conditions. My method of controlling the air is to provide the fan 25 of such capacity that at full speed of the motor 24 the desired amount ofair for high fire conditions is being fed to the burner, and I prefer to allow the motor 24. to run at a constant speed and to reduce the amount of air being passed by the same to the burner for low fire conditions by throttling the 'amount of air which the fan 25 may draw into the, same. I accomplish this result positioning a butterfly valve 51-011 the shaft 52 within the intake passage 28 of the fan 25 and securing to the upper end of the shaft 52 above the passage 28 a lever 53. Rotatably secured to the shaft 52 above the lever 53 is a second lever member 54 provided with a slot .55 as indicated in Fig. 1. The screw 56 projects downwardly through the slot 55 and threadably engages the lever 53andthereby locks the levers 53 and 54 together forequal rotational movement, the rotational position of the lever 54 with respect to the lever 53 being adjusted by loosening the screw 56 and moving the lever 54 within the limits of the slot 55, this adjustment allowing the butterfiy valve 51 to be adjusted for high fire or maximum volume of air passing through the fan .25. On the lower end of the shaft 52 below the casing 28 I provide a third lever 57 secured thereto, thefree end of the lever being provided with a screw 58 which is adapted to bear against a boss (not shown), on the lower surface of the casing 28 to control the low' fire or minimum volume of air being passed through the fan 25,

the screw'58 being threaded inwardl or outwardly to regulate the position-o the butterfly valve 51 for this condition and thus 7 determining the amount of space between the .edges of the butterfly valve 51 and the casing 28 through which air may pass to the fan 25 at lowfire position. The lever 54 is connected by the link 60 to the core or armature 61 of a suitable solenoid 62'which is automatically actuated as described later, in order to move the butterfly valve from low fire to high. fire position.

The oil from the pipe 42 enters the interior of thecasing 43 and passes out of the same into the pipe 44. A' needle valve 65 provided with a suitable indicating and con trolling head 66 cooperates with the valve 63 to limit the amount of oil which may flow through the opening 63' under. the constant head provided for by the supply reservoir,

this serving to regulate the amount of fuel flow ng to the burner for. high fire condii so venturi will now be described.

tions when the maximum amount of oil is being used. A suitable pointer 67 ispreferably provided in conjunction with the control head 66 for visual locationofthe needlevalve 65 with respect to the opening 63. The oil from the pipe 44flows through the solenoid controlled valve 45 which is connected in series with the solenoid valve 62 for the. air supply fan and the supply of current to both of which is controlled by one or more suitable thermostats (not shown) located in the room or rooms heated by the furnace, as will be readily understood. The valve member 45' is so constructed' that when the main flow of oil through the same for high fire-conditions is shut off upon operation of the solenoid, sufficient oil is by-passed past the valve to the pipe 46 to take care of low fire conditions, as is fully explained in my previous patent application above referred to.

As thus far described, the mechanism for providing a maximum and minimum amount of oil and air has been explained, it being understood of course, that the solenoids 73 and, 62 are socontrolled as to furnish a maximum amount of air for the maximum amount of oil and vice versa. The construction of the fire pot and burner nozzle an As shown best in Fig. 3, the fire pot comprises a on -shaped metal part or portion 76 and a re ractory lining 77- conforming in shape to the portion 76, the refractory lining 77 being formed atthe upper edge-thereof to provide aninwardly extending annularflange p0rtion78 which I prefer to term a diaphragm. The upper surface ofthe diaphragm 7.8 recedes from the inner edge thereof in an inwardly and upwardly curved manner. I prefer to so form the lining 77 with respect to the portion 76 so that when these two parts are in cooperative relation-- ship a dead air space such as 79 is formed between the adjacent walls. of the-same, this being an important feature .as will be later described, As previously described, the fire nozzle or venturi is formedintegral with the portion 76 of the fire pot and extends intothe interior thereof in a direction tangential to the interior side face of the refactory material 77, the nozzle being modified in cross section from a circle at its. rearend to an ellipse at the discharge end within the 'fire pot-in order to impart greater'velocity .to" the gas'- being ejected from the same into the fire pot. Formed in the bot tom wall of the fire nozzle, as shown in Figs. 3 and 4, is what ma be termed a well or receptacle 79 provide with a baflle 80 extending upwardly and inwardly from the bottom interior wall of the nozzle 21 at the rear end of the well 79 over the rear portion thereof, thus forming a'li'ood over such e5 portion. This baflie or hood, is provided clear flame and produce no smoke.

with a plurality of openings 80' through the same for the purpose of conducting a metered amount of air through the bafile for a purpose to bedescribedlater. The metal along the edges of the well 79 is formed to provide inwardly-extending flangeportions 81, and received within the well 79 under the flanges 81 is an absorbent pad 82 which may be formed of suitable fibrous asbestos material, or other suitable material, and a screen such as 83 is provided over the upper surface of the pad 82 for maintaining the'same in place and providinga ready passage for oil to the pad and the gases vaporized off of the pad 82 into the nozzle. As indicated in Fig. 3, the oil nozzle 49 is positioned substantially in line with the innor edge of the baflle 80 so that the oil beingfdischarged under low pressure from the same through the openings 50 will drip upon the pad 82. The design of the nozzle the oil that enters the fire pot is in the form I of vaporized gas coming solely from the pad 82. During high fire operation when the maximum blast of air from the fan 22 is passed throu h the fire nozzle 21, a cer tain amount o unvaporized oil particles in the form of a mist may be carried directly into the fire pot without having had the opportunity of being deposited upon the pad 82 and absorbed thereby to be later heated and vaporized into the form of a readily combustible gas. Inasmuch as the pad 82 is of a relatively substantial area,

the baflie 80 is provided atthe rear oft-he same in order to deflect the bulk of the-air upwardly over the pad.- TheopeningsSO' are provided inthe bafiie 80 so that during low fire operation sufiicient air will pass through the openings 80to' form with the vgas being given off from the pad 82 a combustible-mixture whichwhen mixed with the remaining air in the nozzle will burn with a The combined area-of theopenings 80 for this purpose is best determined by actual'ex perience rather than calculation. At the same time, the bafie 80 protects the pad 82 from any sudden blasts of air such as may occur when the butterfly valve 51 is suddenly opened, and thus prevents possible blowing out of the flame above it. The pad 82 in this construction not only serves fuel reserve therein for continuous combus the purposeof the pilot light used in the conventional oil burner system but in addi-' tion serves as the sole means of supplying oil in a vaporized state to the fire pot, it being such as to positively preclude its being extinguished by any blast of air from the fan 25, and such as to provide a sufficient tion for a substantial period of time, for instance, fifteen minutes to one-half hour, depending upon the size and surface area of the pad 82, after the flow of the oil through the nozzle 49 has completely stopped. The flame projected into the fire pot through the nozzle 21, and the combustible mixture which is carried thereby and has its combustion completed within the fire pot, because of the tangential direction in which it is introduced into the fire pot, is caused to swirl around the same and gradually rises upwardly into contact with the diap'hragm 78 and then is forced upwardly ,through the central opening of the same. The flame and gases in passing upwardly through the diaphragm 78 form a low pressure area directly over the diaphragm 78 which acts to pull the flame outwardly and imparts to the same a flat mushroom type of swirl formation. This flame which may be regulated by proper adjustment of the butterfly valve 52 and needle valve 65, may be controlledso as to approach close to but -outof contact with the side walls of the furnace 15 so as to impart the maximum amount of heat to the same without actual contact with it, which would otherwise act to corrode the walls of the furnace with which the flame came in contact. This construction also insures the heat of the combustion coming in contact ,with the lower \portion of the heating surface of the furnace instead of the dome thereof, as is the case in substantially all of the conventional oil burner constructions, and as the dome usually comprises less than fifty per cent of the heat absorbing area of the furnace,

the importance of this feature will be readily recognized, and it will be further readily understood that in obtaining this form of flame I am enabled to obtain a. stack temperature of as low as 200? F. as opposed to a stack temperature of between 600 and 7OO F.' obtained in the usual oil burning mechanism, the saving of -heat as a result of'this feature being enormous.

vUnder high fire conditions, when the maximum amount of oil and air is being fed to the fire pot, a certain amount of oil from the nozzle 49, as, previously described, may be carried into the fire pot in the form of a mist of unvaporized fuel particles such as the conventional constructions depend upon entirely for combustion.

the fire pot, and because of the rotary moof these unvaporized fuel particles from being carried above the fire pot inasmuch as the centrifugal force acting on the particles confines the path of the particles to a point in the fire pot axially outwardly from the inner edge of the diaphragm 78. In forming the refractory lining 77 with the airspace 7 9 between the same and the metallic cup portion 76 I am enabled to heat the refractory material 77 to a substantiallyhigher temperature and degree of incandescence than in the conventional constructions, inasmuch as the air space 79 serves as an insulation between the refractory material 77 and the cup 7 6 and thereby cuts down the conduction and radiation of heat from the cup portion 76 to a minimum. It also serves as a means for allowing the refractory material 77 to be brought to a point of incandescence in a much shorter period of time thanin conventional constructions, and further serves to hold it at such temperature for a relatively greater period of time after the flame within the fire pot has been extinguished.

From the foregoing it will be apparent that the mechanism providedby the present invention discloses a new and novel principle of operation for oil burning devices of the type described in that the heating flame 15 at no time completely extinguished, that the employment of a conventional pilot light of any description is eliminated, that because a material amount of heat is supplied between high fire periods of the apparatus the time necessary to build the heating system to maximum heat value isinateriallv reduced, that for low' fire operation a hunt pletely vaporized gas is furnished for mixture with the air from the fan and that in the high fire operation it is impossible for any unvaporized particles of fuel to escape from the fire pot before complete vaporizat on, and this feature of complete vaporization makes it possible to supply to the fire pot'only suflicient air to insure complete combustion of the oil being fed into the same and thereby eliminates the undesirable feature so common in conventional types of oil burning apparatus of furnishing an excess amount of air to the fire pot in order to atomize the fuel-particles. It will be further apparent that the novel form of fire pot which Ihave provided-serves to produce a flame within the furnace which much more economically coacts with the heating surface of the furnace than in the conventional constructions and this without the employment of any mechanical spreading means of any description whatsoever. The feature of providing the well 79 and cooperating pad 82 I consider a particularly important fea ture of the present invention for by this means I am enabled to obtain a completely gasified oil vapor for low fire combustion, to eliminate the use of a pilot light of any descrpition, and to provide means whereby even after the supply of oil and air to the fire pot has been completely shut off for a substantial length of time the same may be turned on again without danger of an explosion or the introduction of raw oil into the fire pot. Although I have shown in the accompanying drawing and described a variety of separate and distinct features which I have combined to form an oil burner of novel construction and distinct formation it will be recognized, of course, that various of these devices may be eliminated under certain conditions or may be employed in connection with devices of a different type, and I do not limit myself to the employment of the same to the specific assemblage'with parts and to the exact construction shown and described, but desire to state that formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is 1. A nozzle for oil burners provided with a mass of absorbent material therein, means for feeding oil to said mass, means for shielding said mass from the bulk of air v passing through said nozzle, said shielding means permitting a metered quantity of the air passing through said nozzle to pass therethrough and into contact with said mass. v

2. A nozzle for oil burners provided with a mass of absorbent material therein and a shield for deflecting the air passing through said nozzle out of contact with said mass, said shield being provided with a plurality of openings therein, and means for feeding oil to said mass.

3. A mixing device for oil burning apparatus comprising an air passage, a recess formed in said passage, an oil absorbing pad in said.recess, means for feeding oil to said pad, a baflle extending over a ortion of said recess for sealing it from t e flow of air in said baflie.

, 4, A mixing device for oil burning apparatus comprising an air passage, a mass of oil absorbing material in said passage, means for feeding oil to said mass, a bafile passage, and openings in said for directing air out of direct contact with at least aportion of said pad, and openings in said bafile for permitting a metered amount of air to pass through said baflie.

5. A mixing device for oil burning apparatus comprising an air passage, a mass of oil absorbing material in said passage, means for feeding oil to said mass, a bafiie for directing air out of direct contact with at least a portion of said pad, and openings in said bafiie for permitting a metered amount of air to pass through said baflie, the

area'of said openings being such as to per- 

